The present disclosure relates to an exhaust gas guide element for conducting at least a portion of an exhaust gas to a sensor, to a corresponding exhaust gas measuring device, and also to a corresponding method for producing an exhaust gas guide element for conducting at least a portion of an exhaust gas to an exhaust gas sensor.
In existing exhaust gas sensors, the generally electrically heated, ceramic sensor element is exposed directly to the exhaust gas which is to be analyzed. For a newly developed generation of exhaust gas sensors of which the sensor element is designed as a miniature component in a very small installation space in cubic form (as is described in DE102007040726 for example), the main requirements of the installation are as follows:
the operating temperature of novel, miniaturized sensor elements can lie below the temperature of existing sensors and therefore below the maximum exhaust gas temperature. During operation, the sensor should be electrically heated and the temperature controlled to prespecified values in this way. If the exhaust gas temperature at specific operating points of the motor is higher than the operating temperature of the sensor, the installation has to ensure a lower operating temperature at the site of the sensor than the exhaust gas temperature. (In the case of the sensors which have been commercially available to date, a minimum temperature has to be reached, a higher gas temperature is not critical for the sensor element and, in the sense of a lower heating power requirement, is rather desired).
Electrical contact has to be made with the sensor element and said sensor element has to be mechanically fixed. The requirements in respect of the dynamics of the sensor are dependent on the substances which are to be detected by the sensor. Gas should generally be transported to the sensor without delay as far as possible.